Shock-absorber.



H. O. FLETCHER.

SHOCK ABSORBER.

APPLICATION FILED DEC- 27. 1913.

Patented July 4, 1916.

3 SHEETS-SHEET 1 E In uenzor,

H. 0. FLETCHER. suomg ABSORBER.

APPLICATION FILED DEC. 27, I913.

Patented MM, 1916.

3 SHEETS-SHEET 3-' lnuentar they usually come HENRY 0. FLETCHER, OFBOSTON, MASSACHUSETTS.

SHOCK-ABSORBER.

Specification of Letters Patent.

Patented July 4,1916.

Application filed December 27, 1913. Serial No. 369,115; 4

T o all "whom it may concern:

Be it known that I, HENRY O. FLETCHER,

a .citizen of the United States, and residing at Boston, in the countyof Sufiolk, State of Massachusetts, have inventedcertain new and usefulImprovements in Shock-Absorbers for Use on Automobiles and the like, ofwhich the following is a specification.

When automobiles are traveling on rough thoroughfares a great deal ofannoyance and danger to health is caused by the jolt and jar of thevehicle. The springs are normally under some stress due to the weightofthe vehicle body and its occupants, and any slight unevenness in theroad iseasily taken up by the action of the springs due to the fact thatthe sustaining power of the springs and weight of the load are "evenlybalanced, and when the springs are slightly distorted beyondv normal thesustaining power is not increased enoughto overcome the inertia of theload so as to give it a perceptible movement. When the wheels of thevehicle strike an obstacle the springs are momentarily broughtundergreat stress, and their sustaining power greatly increased, so thatit overcomes the inertia of the load and suddenly lifts the body, manytimes raising thepassengers off their seats. As the inertia of the loadis now overcome, it continues to riseuntil the springs are opened sothat they have no sustaining power, but instead have a tendency tosuddenly lower the body of ,the vehicle until they, are again compressedby its inertiaand weight, and again the body is raised by the addedsustaining power due to this compression. The latter mentioned movementsof the vehicle body usuallytake place while the passengers are raisedfrom their seats and as they descend down on the seats during theupwardmoveinent of the latter, greatly to their discomfort. scend into arut the body descends, coming down with a jolt and compressing thesprings which, in turn, again suddenly raise the body, causing avibratory movement of the body and its occupants.

Repeated shocks of this kind' are very injurious to the physicalorganism of the human body and it is the object .of my invention toovercome these sudden jolts by par- Vhen the wheels de-.

tially overcoming or retarding the action of the springs in bothdirections when they are abnormally compressed. I

Another object of my invention is, while it reduces the sudden orabnormal actions of the springs, not to interfere with their normalaction, for such interference would decrease their elastic; quality andwould have the'eifect of stiffening the spring and impa1r the comfort ofthe passengers.

F igure 1 is a side elevation, parts being 'broken away for clearness ofillustration.

Fig. 2 is a front-elevation showing a section on the line A, B, Fig. 1.Fig. 3 is a plan and Fig. 4 is an elevation of the vertical slidingpiston. Fig. 5 is. an end view and Fig. 6 is a plan view of the sleevesin which the horizontal plungers slide. Figs. 7 and 8 are end and planviews, respectively, of the horizontal plungers and Fig. 9 is a diagramshowing the relative movements of the piston and plungers.

In the drawings like characters represent like parts.

To the body or case 1, is attached the connection 2, which is pivotallyattached at 3, to the lower spring or axle housing of the vehicle. Thepiston 4, is pivotally attached at 5, to the upper spring or body of thevehicle and freely slides in the body or case 1, which is suitably boredout to receive it.

The stufiing box '6, acts as a guide to keep,

ance of-a cross. Y

as nearly full I, as practicable, with a suitable liquid, which The bodyor case 1, is filled is prevented from leaking or evaporating by thestufiing box 6, containing the packing 12, the plugs 13, 13, and theconnection 2, which is made in the form of and acts as a plug. I

The parts are made and assembled so that when the vehicle is normallyloaded the pivot 8, is near the central portion of its travel and thelinks in a horizontal position, or nearly so, and any slight movement ofthe vehicle body relative to that of the axle causes a correspondingmovement of the piston 4. As the links 7, 7, are in the form of a togglethe movement of the plungers 10, 10, is so slight that it may beconsidered negligible.

A greater movement of the vehicle body causes a corresponding greatermovement of the piston 4, and consequently of the pivot 8 and as itdescends toward the lower extremity of its travel the links 7, 7, haveto work through a greater angularity and cause the plungers 10,-10,totravel at a greater rate of speed relative to that of the plunger 4,the extremeposition being represented by the dotted lines 5, 7, 7 8 9 9.

The movement of the parts is clearly illustrated by the diagram F ig; 9.While the piston pivot 8, travels from 14 to 14, the plunger pivots 9,9, have a motion from 17 to 16 and back to 17 during the travel of thepivot 8, from 14 to 18 or from 14 to 18 the pivots 9, 9, travel from 17to 20; and while the pivot 8, moves from 18 to 19, or from 18 to 19- thepivots 9, 9, move from 20 to 21.

Conversely as the pivot 8 is moved from 19 to 18 or from 19 to 18thepivots 9, 9, travel from 21 to 20; as the pivot 8, travels from 18 to-14 or from 18 to 14 the pivots 9, 9, travel from 20 to 17; and whilethe piston pivot 8, moves between 14 and 14 the plunger pivots 9, 9, areconfined to a movementbetween 16 and 17. I

The plungers 10, 10, are fitted to the sleeves 11, 11, so as not toallow passage of the liquid contained in the body 1, and are providedwith small holes 23, 23, through which the liquid passes as the plungers10, 10, move back and forth in the sleeves 11, 11. The adjusting screws24, 24, are provided with passages 25, 25, which are eccentric to thecenter of the screws and consequently out of line with the passages 23,23, so that, when the screws 24, 24, bottom, no liquid can pass, butwhen they are slightly relieved the liquid can pass through the passages23, 23, between the end of the screws 24, 24, and the bottom of thescrew holes, thence through the passages 25, 25, as shown by the arrows.When the plungers 10, 10, move toward each other the liquid passes inthe direction of the arrows and when the plungers move a w a v from eachother the direction of flow of the liquid is reversed. \Vhen the piston4, is traveling near its extreme downward or upward movements, therelative speed of the plungers 10. 10, is greatly increased, due to theangularity of the connecting rods 7, 7, which forces the liquid throughthe passages 23, 23, 25, 25, much faster, greatly increasing theresistance offered by the piston 4, to the movement of the vehicle body.This resistance is also greatly augmented due to the fact that thepiston 4, when near these extreme positions has to move the plungers 10,10, by'applying its force angularly to the direction of their ,travelinstead of directly.

By the foregoing it will be seen that the force tending to move theplungers 10, 10, in either direction becomes more indirect as the piston4, nears its extreme upward or downward movement, due to the angularityof the links 7, which increases the resistance to themovements of thepiston 4, at these positlons' and consequently to those of thesprings-when they are under their greatest stresses.

By this arrangement of parts the resistance to themovements .of thevehicle springs "aries with the stress, but in a much greaterproportion, which allays their sudden movements either in a downward orupward di rection, thus overcoming the jolting and bouncing action ofthe vehicle body.

As some vehicles have light bodies mounted on comparatively stitt'springs and others have heavy bodies supported bycomparativel-y lightsprings it is necessary to have some kind of adjustable resistance thatmay be applied to any point of the movement of the plungers 10, 10. Thisadjustment I have provided by means of the adjusting screws 26, 26, 27,27, 28, 28, which are adapted to distort the sleeves 11, 11, by pressingagainst the plates 29, 29, which in turn transmit the pressureto thesleeves 11, 11, through the slightly yielding mediums which I have shownin the form of packing 30, 30, which may be composed of leather, rubber,spring metal or other yielding material. When more resistance isdesired, at the extreme inward posit-ions of the plungers 10, 10, thescrews 26, 26, may be adjusted inward; if an increase of resistance isneeded near the central movements the screws 27 27 may be turneddownward; if the extra resistance is desired near the outward positionsof the sleeves 11,111, the screws 28, 28, are turned to give thepressure desired.

I have shown three adjusting screws to each plunger but it is tobeunderstood that any practicable number of screws may be employed forthis purpose.

In many cases the resistance caused by the pressure of the adjustingscrews 26, 26, 27 27, 28, 28, is not needed, in which case the device isoperated by means of the resistance of the liquid alone, and it will beseen that the device may be operated by means of the resistance causedby the pressure of the adjusting screws alone, the liquid being omitted,which in some cases is preferable.

I donot limit my invention to either of the above mentioned ways ofaccomplishing the desired purpose or to a combination of leaking pastthem, but I have preferred to fit them to-the body 1,'in such a mannerthat packing is not needed.

I have preferably employed two plungers but one, or more than two, couldbe used.

I have preferred to call the plungers 10, 10, by that name todistinguish them from the piston 4, but the name piston would be asapplicable and in the claims I have spoken of them as pistons as well asplungers.

The piston 4, could be fitted to the body 1, in such a manner as toprevent the liquid leaking by it and provided with a passage to offerresistance to the movements of the vehicle body, but I have preferred toallow free passage of the. liquid by it for the reason that theresistance would be applied whenit would be a detriment.

I am aware that many other additions and changes in form and arrangementof parts may be resorted to without departing from the spirit and scopeof my invention.

What I claim as new is set forth in the following claims:

1. In an apparatus of the kind described, vehicle running gear and bodyelements,"a piston connected to and adapted-to take the motion of one ofsaid elements, a tightly sealed frame or case, in which the piston 5 isadapted to reciprocate, said case contain mg a suitable liquid, andconnected to and adapted to take the motion of the other element,resisting plungers having passages through which the.liquid passes fromone chamber of the case to another during the motion of the plungers inboth directions and connecting links pivotally connected both to thepiston and plungers.

2. In an apparatus of the kind described, vehicle running gear and bodyelements, a piston connected to,and adapted to take the motion of one ofsaid elements, a tightly sealed frame or case, in which the piston isadapted to reciprocate, said case containing a suitable liquid, andconnected to and adapted to take the motion of the other element,resisting plungers having adjustable passages through which the liquidpasses from one chamber of the case to another during the motion of theplungers in both directions, and connecting links piv- .otally connectedboth tothe piston and plungers.

3. In an apparatus of the kind described, vehicle running gear and bodyelements, a piston connected to and adapted to take the motion of one ofsaid elements, a frame or case in which the piston is adapted toreciprocate and which is adapted .to take the motion of the otherelement, sliding resisting members carried by said frame, connectinglinks pivotally connected to both the piston and resisting members andmeans to apply frictional resistance .tothe motion of the resistingmembers in both directions oftheir travel;

4. In an apparatus of the kind'described, vehicle running gear and bodyelements, a piston connected to and adapted to take" the motion of oneof said elements, a frame" or case 'in which the piston'is adapted toreciprocate, said case adapted to take the motionof the other element,sliding resist, ing members carried by said frame, connecting linkspivotally connected to both the piston and resisting members andadjustable means to apply frictional resistance to the motion of theresisting members in both directions of their travel.

5. In .a shock absorber, a piston element and a body element, havingrelative movement' to each other, resisting members, carried by the bodyelement, connecting links pivotally connected .to 'both the pistonelement and the resisting members and means 'to frictionally resist themovement of the.

resisting members in both directions of their travel.

6. In a shock absorber, a body element adapted to carry a suitableliquid, a piston element having relative movement to the body element,resisting plungers having passages to allow the liquidto from 1 g onechamber to another in the body e ement' during movement of the plungersin both directions, and means to operate the resisting plungers by thepiston element.

7 In a shock absorber, a body element. adapted to carry a suitableliquid, a piston element having relative movement to the body element,resisting plungers having adjustable passages to allow the liquid topass from one chamber to another in the body element during movement ofthe plungers in/both directions, and means to operate the resistingplungers by the piston element.

8. In a shock absorber, two elements having relative movement to eachother, re-

- sisting members carried by one of said elements, connecting linkspivotally connected to the other element and also to the resist ingmembers, and means to frictionally resist the movement of the resistingmembers in both directions of their travel.

9. In a shock absorber, the combination with two elements capable ofmovement relative to each other, of one or more reciprocating resistingmembers, means connecting said resisting members to one of said elementsby which said resisting members are caused to move in the same directionwhen the said two elements move relative to each other in eitherdirection from their relative normal position, and means to resist themovement of the resisting members throughout the entire extent of theirtravel.

10. In a shock absorber, the combination with two elements capable ofhaving movement relative to each other, of one or more reciprocatingresisting members, connections between said resisting members and one ofsaid elements by which said resisting members are caused to move in thesame direction when the said two elements move relative to each other ineither direction from their relative normal position and in the oppositedirection when said eleme'nts' move relative to each other ineitherdirection toward their relative normal position, and means to resist themovement of the resisting members in both directions of their travel.

11. In a shock absorber, the combination with vehicle running gear andbody elements capable of having movement relative to each other, of oneor more reciprocating resisting members, connections between saidresisting members and one of said elements by which said resistingmembers are caused to move in the same direction when the said twoelements move relative to each other in either direction from theirrelative normal position, and means to apply an approxi= mately uniformresistance to the movement of the resisting members throughout theentire extent of their travel.

12. In a shock absorber, two elements having relative movement to eachother, re-

sisting members carried by one of said elements, means to reciprocatethe resisting members positively in both directions by connecting linkspivotally connected to the other element and to the resisting members,and adjustable means to frictionally resist the movement of theresisting members in both directions of their travel.

13. In an apparatus of the kind described, vehicle running gear and bodyelements, a piston connected to and adapted to take the motion of one ofsaid elements, a tightly sealed frame or case in which the piston isadapted to reciprocate, said case containing a suitable liquid andconnected to and adapted to take the motion of the other element,resisting plungers, passagesbeing provided through which the liquidpasses from one chamber of the case to another during the motion of theplungers in both directions, and connecting links pivotally connectedboth to the piston and plungers. 14. In a shock absorber, thecombination with two elements having. movement relative to each other,of one or more resisting members, positive connections between saidresisting members and one of said elements whereby relative movement ofsaid elements gives movement to said resisting members, means associatedwith the other element and operating to guide the resisting members intheir movement and also to apply the same resistance to the movement ofthe resisting members in both directions of their travel.

In witness whereof I hereunto set-'my hand in the presence of twowitnesses.

HENRY O. FLETCHER. \Vitnesses:

FREDERICKA SMITH, L. MABEL HODGDON.

